Early-est:     South Sandwich Islands Region    2026.08.12-11:47:20.59    q:B      mb:5.2*    Mwp:6.0    Mwpd:-    Td*T50Ex:2.3     fmamp_polarity:./hypo.1786535242378.mech.fmamp_polarity.thumb.jpg     fmamp_polarity_waveform:./hypo.1786535242378.mech.fmamp_polarity_waveform.thumb.jpg     hash:./hypo.1786535242378.mech.hash.thumb.jpg

Automatic solution - this event has not been reviewed by a seismologist
Automatically determined event information may be incorrect!

Earthquake Details:
Magnitude: mb: 5.2* [27]    Mwp: 6.0 [11]    Mwpd: 6.2Xinv [9]
Region: South Sandwich Islands Region
Origin Time: 2026.08.12-11:47:20.59 UTC
Hypocenter: lat: -60.22°  lon: -29.19°  [+/-16km]    depth: 55km  [+/-37km]
Location Quality: qualityCode:  B     stdErr: 1.0s   assocPhases: 73   usedPhases: 33
minDist: 7.1°   maxDist: 151.8°   AzGap: 54°   2ndAzGap: 85°   atten: -0.99 [+/-0.36]
Location Uncertainty: 68%ConfEllipse:   minHorUnc: 12km   maxHorUnc: 16km   azMaxHorUnc: 180°
68%ConfEllipsoid:   semiMajorAxisLength: 37km   majorAxisAzimuth: 142°   majorAxisPlunge: 86°   semiIntermediateAxisLength: 20km   intermediateAxisAzimuth: 0°   intermediateAxisPlunge: 3°   semiMinorAxisLength: 15km
Tsunamigeneic Assesment:
Discriminants: Prob Underwater: >99%
T50Ex: 0.5 [24]    Td: 5.0s [11]    Td*T50Ex: 2.3 [11]    To: 10.2s [21]
Closest plate boundaries:
   Sandwich - Scotia [oceanic transform fault]: distance: ~30km
   Scotia - Antarctica [oceanic transform fault]: distance: ~50km
   Sandwich - Antarctica [oceanic transform fault]: distance: ~90km
   Antarctica - South America [oceanic transform fault]: distance: ~170km
   Sandwich / South America [subduction zone]: distance: ~170km
Subduction geometry: none or not available
Decision table (TEST!):
Event type: Subduction Zone Other Thrust/Normal Strike-slip
Compatible close plate boundary?:
 YES (170km)
 no
 YES (30km)
Prob underwater:
 >99%
 >99%
 >99%
Td*T50Ex:
   2.3
   2.3
   2.3
Td*To:
     51.0
     51.0
     51.0
Mwp magnitude:
       6.0
       6.0
       6.0
Hypocenter depth:
       55km
       55km
       55km
Slab depth at epicenter:
       n/a
       -
       -
Tsunami and Rupture predictions (TEST!): No prediction: Event too small (Mwp<7.0) or too few Mwp readings (N<20)
./hypo.1786535242378.map.jpg

First-motion Focal Mechanism (FMAMP_POLARITY):    (Warning: Unreliable solution, qualityCode=C)
Nodal Plane 1: strike: 71°   dip: 55°   rake: 167°
Nodal Plane 2: strike: 169°   dip: 79°   rake: 35°
Quality: azimuthalGap: -1°   stationPolarityCount: 30   misfitWeightCount: 9.0   misfit: 0.11   stationDistributionRatio: 0.49   meanDistP: 43.4   meanDistT: 40.9   qualityCode: C
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity
./hypo.1786535242378.mech.fmamp_polarity.mechanism.jpg
First-motion Focal Mechanism (FMAMP_POLARITY_WAVEFORM):    (No solution available)
Nodal Plane 1: strike: 0°   dip: 0°   rake: 0°
Nodal Plane 2: strike: 270°   dip: 90°   rake: 90°
Quality: azimuthalGap: -1°   stationPolarityCount: 0   misfitWeightCount: -1.0   misfit: -1.00   stationDistributionRatio: -1.00   meanDistP: -1.0   meanDistT: -1.0   qualityCode: X
Method: methodID: smi:net.alomax/focalmec/fmamp_0.0.5X_2016.06.14/_polarity_waveform
./hypo.1786535242378.mech.fmamp_polarity_waveform.mechanism.jpg
First-motion Focal Mechanism (HASH):    (Warning: VERY UNRELIABLE SOLUTION, qualityCode=D)
Nodal Plane 1: strike: 86°   dip: 88°   rake: -166°
Nodal Plane 2: strike: 355°   dip: 76°   rake: -2°
Quality: azimuthalGap: 54°   stationPolarityCount: 30   misfit: 0.32   stationDistributionRatio: 0.62   rmsAngDiffAccPref: 42.62   fracAcc30degPref: 0.65   qualityCode: D
Method: methodID: smi:gov.usgs/focalmec/HASH_1.2
./hypo.1786535242378.mech.hash.mechanism.jpg

Event ID: smi:alomax.net_BETA/author/ee/event/1786535242378
Event info last updated: 2026.08.12-12:46:00 UTC
Event first association/location: 2026.08.12-11:56:01 UTC
Software: Early-est 1.2.10 (2024.02.23)
Agency: alomax.net_BETA